Meringue-like aerogel could make aircraft quieter

Researchers at the University of Bath in the United Kingdom have developed an extremely light material that can reduce aircraft engine noise and improve passenger comfort.

The graphene oxide-polyvinyl alcohol aerogel weighs only 2.1kg/m³, one of the lowest values ever reported for acoustic insulation. It could be used as insulation within aircraft engines to reduce noise by up to 16dB – decreasing the 105dB roar of a jet engine taking off to a sound closer to that of a hair dryer.

The aerogel’s meringue-like structure could act as an insulator within aircraft engine nacelles while adding almost no weight. Currently, the team is optimizing the material to improve heat dissipation, which benefits fuel efficiency and safety.

Researchers from Bath’s Materials and Structures Centre (MAST) have published a method for manufacturing the materials in the journal Scientific Reports.

Professor Michele Meo, who led the research, says, “This is clearly a very exciting material that could be applied in a number of ways – initially in aerospace but potentially in many other fields such as automotive and marine transport, as well as in building and construction.

“We managed to produce such an extremely low density by using a liquid combination of graphene oxide and a polymer, which are formed with whipped air bubbles and freeze-casted. On a very basic level, the technique can be compared with whipping egg whites to create meringues – it’s solid but contains a lot of air, so there is no weight or efficiency penalty to achieve big improvements in comfort and noise.”

Although the team’s initial focus is working with aerospace partners to test the material as a sound insulator in aeroplane engines, they say it could also be used to create panels in helicopters or car engines. They estimate that the aerogel could be in use within 18 months.

University of Bath

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